The present invention relates to a crosslinked resin composition and more particularly to a resin composition superior in fluidity, permanent elongation and heat resistance, obtained by crosslinking a composition comprising a polypropylene resin and an ethylene copolymer of an extremely low density which copolymer is obtained by copolymerizing ethylene with an .alpha.-olefin in the presence of a specific catalyst.
Polypropylene has widely been used as automobile parts, electric household products and parts and mechanical parts because of its superior mechanical physical properties. However, it is inferior in impact strength, especially impact strength at low temperatures, and therefore its application range is limited. In order to remedy such a drawback, there have been proposed several methods in which polypropylene is blended with a rubber component. For example, in Japanese Patent Laid Open No. 157839/83 there is described a resin composition comprising a specific ethylene/.alpha.-olefin copolymer and polypropylene. Although this composition has an improved impact strength, it is not so greatly improved in fluidity and heat resistance, nor is it improved in permanent elongation. Thus there remain problems in point of moldability and physical properties of molded products.